Sensorimotor faculties bias perceptual decision-making.

Decision-making is a deliberate process that seemingly evolves under our own volition. Yet, research on embodied cognition has demonstrated that higher-order cognitive processes may be influenced, in unexpected ways, by properties of motor and sensory systems. Here we tested whether and how simple decisions are influenced by handedness and by asymmetries in the auditory system. Right- and left-handed participants performed an auditory decision task. In the task, subjects decided whether they heard more click sounds in the right ear or in the left ear, and pressed a key with either their right or left index finger, according to an instructed stimulus-key assignment (congruent or reversed). On some trials, there was no stimulus and subjects could choose either of the responses freely. When subjects chose freely, their choices were substantially governed by their handedness: Left-handed subjects were significantly biased to make the leftward choice, whereas right-handed subjects showed a substantial rightward bias. When the choice was governed by the sensory stimulus, subjects showed a rightward choice bias under the congruent key assignment, but this effect reversed to a leftward choice bias under the reversed key assignment. This result indicates a bias towards deciding that there were more clicks presented to the right ear. Together, our findings demonstrate that human choices can be considerably influenced by properties of motor and sensory systems.

Visual Distraction's "Silver Lining": Distractor Suppression Boosts Attention to Competing Stimuli.

Efficient search of the environment requires that people attend to the desired elements in a scene and ignore the undesired ones. Recent research has shown that this endeavor can benefit from the ability to proactively suppress distractors with known features, but little is known about the mechanisms that produce the suppression. We show here in five experiments (N = 120 college students) that, surprisingly, identification of a sought-for target is enhanced when it is grouped with a suppressed distractor compared with when it is in a different perceptual group. The results show that the suppressive mechanism not only downweights undesired elements but also enhances responses to task-relevant elements in competition for attention with the distractor, fine tuning the suppression. The findings extend the understanding of how people efficiently process their visual world.

Feature-blind attentional suppression of salient distractors.

A recent paper has reported, for the first time, that people are capable of suppressing salient singleton distractors of unknown color if the search task requires them to search for the most prevalent of several shapes in the display. We identify here several potential limitations of the earlier findings. In particular, in the reported experiments, the likelihood of a salient distractor was higher than what is typically studied, the distractor object was similar in shape to the relevant objects, only two colors were studied, the distractor was consistently a fixed shape, and the distractor was always a unique shape different from the search targets. Each of these limitations leaves open some questions about the generality of the findings. We address each of the concerns here, and show, in five experiments, that the ability to suppress distractors of unknown color is a robust finding that is not compromised by the potential limitations identified. When searching for the most prevalent of several shapes in a display, people can indeed suppress capture by otherwise-salient color singleton distractors even when their color is not known in advance (i.e., in a feature-blind manner), facilitating efficient search. The experiments confirm the ability to suppress visual elements based on second-order (e.g., a unique color) or global salience information, and not merely based on first-order (e.g., a specific color) information.

Ignoring the unknown: Attentional suppression of unpredictable visual distraction.

Recent findings have shown that people are capable of proactively inhibiting salient visual distractors in a scene when they know the color of the distractor, enhancing efficient search. Investigations of this suppression effect have concluded that it is not possible to suppress a distractor of an unknown color, implying a mechanism that operates only on a first-order, feature-specific level. However, with a modification to the search task, we show here for the first time that people can indeed suppress salient uniquely colored distractors even when not knowing their color in advance. The task requires participants to search for the most prevalent of several shapes in the display. In two experiments the presence of an unpredictable-color singleton facilitated search. An experiment with briefly presented probes confirmed proactive prevention of capture by the distractor. The results reveal a second-order or global-salience-based suppressive mechanism that facilitates visual processing. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Spatial task relevance modulates value-driven attentional capture.

Attention tends to be attracted to visual features previously associated with reward. To date, nearly all existing studies examined value-associated stimuli at or near potential target locations, making such locations meaningful to inspect. The present experiments examined whether the attentional priority of a value-associated stimulus depends on its location-wise task relevance. In three experiments we used an RSVP task to compare the attentional demands of a value-associated peripheral distractor to that of a distractor associated with the top-down search goal. At a peripheral location that could never contain the target, a value-associated color did not capture attention. In contrast, at the same location, a distractor in a goal-matching color did capture attention. The results show that value-associated stimuli lose their attentional priority at task-irrelevant locations, in contrast to other types of stimuli that capture attention.

Recruitment of newly acquired category exemplars into unconscious processing systems is rapid and durable.

In a series of 3 unconscious priming experiments, we investigated if newly acquired English language words can become integrated into unconscious processing systems, and what preconditions are required to enable this process. In each experiment participants learned English language names of extremely rare fish and flowers in a single learning session. After a varying interval of time and in some cases a brief session of repeated conscious exposure (relearning), the newly learned words were presented as briefly flashed, visually masked primes in a standard unconscious category priming procedure. Results show that newly acquired words are recruited quickly into unconscious processing systems. Furthermore, this acquisition persists for at least 48 h and is dependent on prime duration. Since priming was only obtained after an interval that included overnight sleep, consolidation during sleep may play a role in the integration of novel words into unconscious processing systems.

Contributions of gains and losses to attentional capture and disengagement: evidence from the gap paradigm.

It is known that movements of visual attention are influenced by features in a scene, such as colors, that are associated with value or with loss. The present study examined the detailed nature of these attentional effects by employing the gap paradigm-a technique that has been used to separately reveal changes in attentional capture and shifting, and changes in attentional disengagement. In four experiments, participants either looked toward or away from stimuli with colors that had been associated either with gains or with losses. We found that participants were faster to look to colors associated with gains and slower to look away from them, revealing effects of gains on both attentional capture and attentional disengagement. On the other hand, participants were both slower to look to features associated with loss, and faster to look away from such features. The pattern of results suggested, however, that the latter finding was not due to more rapid disengagement from loss-associated colors, but instead to more rapid shifting of attention away from such colors. Taken together, the results reveal a complex pattern of effects of gains and losses on the disengagement, capture, and shifting of visual attention, revealing a remarkable flexibility of the attention system.

Simple action alters attention towards visual features.

Recent studies have revealed an action effect, in which a simple action towards a prime stimulus biases attention in a subsequent visual search in favor of objects that match the prime. However, to date the majority of research on the phenomenon has studied search elements that are exact matches to the prime, and that vary only on the dimension of color, making it unclear how general the phenomenon is. Here, across a series of experiments, we show that action can also prioritize objects that match the shape of the prime. Additionally, action can prioritize attention to objects that match only one of either the color or the shape of the prime, suggesting that action enhances individual visual features present in the acted-on objects. The pattern of results suggests that the effect may be stronger for color matches - prioritization for shape only occurred when attention was not drawn to the color of the prime, whereas prioritization for color occurred regardless. Taken together, the results reveal that a prior action can exert a strong influence on subsequent attention towards features of the acted-on object.

Ensemble perception without attention depends upon attentional control settings.

People are able to rapidly extract summary statistical information about common patterns, or ensembles, that may exist in a scene, such as repeated textures or colors. Here we examined the extent to which such an ensemble perception can occur in the absence of focal visual attention using a method that has some advantages over methods previously used to study the issue. In particular, we assessed the extent to which ensembles can be processed without attention by measuring the indirect effect of a to-be-ignored ensemble on judgments of an attended ensemble. The results show that ensembles outside the focus of attention do influence judgments of attended ensembles when the to-be-ignored ensemble contains summary statistics that match a sought-for target category. Thus, an attentional control setting for specific summary statistical information permits the processing of ensembles outside of focal attention, facilitating the rapid perception of visual scenes.

Approach and avoidance movements modulate value-driven attentional capture.

Recent studies have shown that visual features that were previously associated with a high monetary reward attract visual attention, a finding referred to as value-driven attentional capture. Given the fact that a reward often follows an action, the present study examined how approach and avoidance movements made to achieve a reward might modulate value-driven attentional capture. Experiment 1 revealed that a color that was previously associated with a high reward was more likely to capture visual attention than a color that was previously associated with a low reward, but only when the reward had been achieved by an approaching movement. In contrast, when the reward had been achieved by an avoiding movement, a color that was associated with a low reward was more likely to capture attention than a color that was associated with a high reward. Experiment 2 replicated the key findings of Experiment 1. Experiment 3 showed that approaching and avoiding movements do not modulate attentional capture on their own, in the absence of any reward. Overall, the present study revealed for the first time that visual features that were previously associated with compatible action and reward pairs prioritize visual selection. These novel findings show how the history of action and reward interactively modulates visual selection. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Standing enhances cognitive control and alters visual search.

Postural changes and the maintenance of postural stability have been shown to affect many aspects of cognition. Here we examined the extent to which selective visual attention may differ between standing and seated postures in three tasks: the Stroop color-word task, a task-switching paradigm, and visual search. We found reduced Stroop interference, a reduction in switch costs, and slower search rates in the visual search task when participants stood compared to when they sat while performing the tasks. The results suggest that the postural demands associated with standing enhance cognitive control, revealing broad connections between body posture and cognitive mechanisms.

Motion onset really does capture attention.

Several properties of visual stimuli have been shown to capture attention, one of which is the onset of motion. However, whether motion onset truly captures attention has been debated. It has been argued that motion onset only captured attention in previous studies because properties of the animated motion used in those experiments caused it to be "jerky" (i.e., there were gaps between successive images during animated motion). The present study sought to determine whether natural motion onset captures attention. Additionally, the present study further examined the circumstances under which animated motion onset, the only type of motion onset that can be produced on a computer display, does and does not capture attention. In Experiment 1, participants identified target letters in search arrays containing distinct animated motion types, either accompanied or unaccompanied by a new object. Animated motion onset captured attention, but not when the motion onset was accompanied by a new object, indicating that prior failures to replicate capture by animated motion onset were limited because a new object had always been included in the display. Experiment 2 employed natural motion rather than animated motion and found that participants were fastest at identifying motion-onset targets compared to other target types. These results provide further support for the claim that motion onset captures attention.

Effects of environmental support on overt and covert visuospatial rehearsal.

People can rehearse to-be-remembered locations either overtly, using eye movements, or covertly, using only shifts of spatial attention. The present study examined whether the effectiveness of these two strategies depends on environmental support for rehearsal. In Experiment 1, when environmental support (i.e., the array of possible locations) was present and participants could engage in overt rehearsal during retention intervals, longer intervals resulted in larger spans, whereas in Experiment 2, when support was present but participants could only engage in covert rehearsal, longer intervals resulted in smaller spans. When environmental support was absent, however, longer retention intervals resulted in smaller memory spans regardless of which rehearsal strategies were available. In Experiment 3, analyses of participants' eye movements revealed that the presence of support increased participants' fixations of to-be-remembered target locations more than fixations of non-targets, and that this was associated with better memory performance. Further, although the total time fixating targets increased, individual target fixations were actually briefer. Taken together, the present findings suggest that in the presence of environmental support, overt rehearsal is more effective than covert rehearsal at maintaining to-be-remembered locations in working memory, and that having more time for overt rehearsal can actually increase visuospatial memory spans.

Action influences unconscious visual processing.

It has long been known that action is tightly linked to visual perception. In support of this connection, recent studies have shown that making a simple action towards a visual object can bias subsequent visual processing of features of the acted-on object. The present study examined whether conscious awareness of the acted-on object is necessary to yield this action effect. In two experiments, we found that making an action towards an invisible object resulted in greater priming in a subsequent visual search task. This shows that conscious awareness is not necessary to obtain the action-induced visual bias. More importantly, the result implies that action might amplify the sensory signal from the subliminally presented object, which is presumed to occur during early visual processing.

Simple actions activate semantic associations.

It is well known that words can prime the identification of related pictures. But how are these connections between words and their visual representations prioritized? Here we show that action modulates word-picture priming. Participants in three experiments either did nothing or made a simple, arbitrary action (a keypress) while reading a word. Next, they searched for a target that was superimposed on one of several images. In some trials, the target was on an image that represented the previously seen word; in other trials, that image contained a distractor. The word primed the picture during visual search, such that targets on that (task-irrelevant) image were found more quickly. Importantly, the magnitude of this word-picture priming was greater if participants had made an action while reading the word. These results are the first to implicate action as a factor that can modulate word-picture associations, and they show that the effects of action on perception are more profound than has previously been believed: Elements that share only semantic (but not sensory) overlap with acted-on objects receive attentional priority.

Tool use produces a size illusion revealing action-specific perceptual mechanisms.

In four experiments, participants estimated the sizes of target objects that were either out of reach, or that could be reached by a tool (a stylus or laser pointer). Objects reachable with the aid of a tool were perceived to be smaller than identical objects without a tool. Participants' responses to questioning rule out demand characteristics as an explanation. This new size illusion may reflect a direct impact of tool use on perceived size, or it may stem from the effects of tool use on perceived distance. Both possibilities support action specific accounts of perception.

A rare highly aggressive tumour: lymphoepithelioma-like thymic carcinoma.

Lymphoepithelioma-likethymic carcinoma is a rare neoplasm that presents with compressive symptoms or as an incidental radiological finding of an anterior mediastinal mass. It is an aggressive carcinoma with a high rate of invasion, metastasis and recurrence. Its diagnosis usually carries a poor prognosis largely due to propensity for late diagnosis. To date, guidance for treatment remains limited. This is a case of lymphoepithelioma-like thymic carcinoma in a young male adult who presented initially with back pain. Despite prompt initiation of chemotherapy with cisplatin, doxorubicin and cyclophosphamide, he had a complicated hospital course leading to demise within 2 months of diagnosis.